Add message IDs, transport interface, client package, extract protocol headers

lib/picoserial/picoserial.go

@@ -21,29 +21,29 @@ func FindDevice() (string, error) {
 	return "", nil
 }
 
-func Open(portName string) (serial.Port, error) {
-	return serial.Open(portName, &serial.Mode{BaudRate: 115200})
+type SerialTransport struct {
+	port serial.Port
 }
 
-// SendAndReceive sends data and reads the response with a timeout.
-func SendAndReceive(portName string, data []byte, timeout time.Duration) ([]byte, error) {
-	port, err := Open(portName)
+func Open(portName string) (*SerialTransport, error) {
+	port, err := serial.Open(portName, &serial.Mode{BaudRate: 115200})
 	if err != nil {
 		return nil, fmt.Errorf("opening %s: %w", portName, err)
 	}
-	defer port.Close()
+	return &SerialTransport{port: port}, nil
+}
 
-	port.SetReadTimeout(timeout)
-
-	_, err = port.Write(data)
-	if err != nil {
-		return nil, fmt.Errorf("writing to %s: %w", portName, err)
-	}
+func (t *SerialTransport) Send(data []byte) error {
+	_, err := t.port.Write(data)
+	return err
+}
 
+func (t *SerialTransport) Receive(timeout time.Duration) ([]byte, error) {
+	t.port.SetReadTimeout(timeout)
 	var resp []byte
 	buf := make([]byte, 256)
 	for {
-		n, err := port.Read(buf)
+		n, err := t.port.Read(buf)
 		if n > 0 {
 			resp = append(resp, buf[:n]...)
 		}
@@ -53,3 +53,7 @@ func SendAndReceive(portName string, data []byte, timeout time.Duration) ([]byte
 	}
 	return resp, nil
 }
+
+func (t *SerialTransport) Close() error {
+	return t.port.Close()
+}